Lists the prerequisites to create database links from an Autonomous Database to a target Oracle database that is on a private endpoint.

Use DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK to create database links from an Autonomous Database to a target Oracle database that is on a private endpoint and connect without a wallet (TCP).

1. On Autonomous Database create credentials to access the target database. The username and password you specify with DBMS_CLOUD.CREATE_CREDENTIAL are the credentials for the target database used within the database link, (where the target database is accessed through the VCN).

   For example:

   BEGIN
        DBMS_CLOUD.CREATE_CREDENTIAL(
            credential_name => 'PRIVATE_ENDPOINT_CRED',
            username => 'NICK',
            password => 'password'
            );
   END;
   /

   The characters in the username parameter must be all uppercase letters.

   Note
   
   You can use a vault secret credential for the target database credential in a database link. See Use Vault Secret Credentials for more information.

   This operation stores the credentials in the database in an encrypted format. You can use any name for the credential name.

2. Create the database link to the target database using DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK.

   For example:

   BEGIN
        DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK(
            db_link_name => 'PRIVATE_ENDPOINT_LINK', 
            hostname => 'exampleHostname',
            port => '1522',
            service_name => 'exampleServiceName',
            ssl_server_cert_dn => NULL,
            credential_name => 'PRIVATE_ENDPOINT_CRED',
            directory_name => NULL,
            private_target => TRUE);
   END;
   /

   For a target on a private endpoint, DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK supports specifying a single hostname with the hostname parameter. On a private endpoint, using an IP address, SCAN IP, or a SCAN hostname is not supported (when the target is on a public endpoint, CREATE_DATABASE_LINK supports using an IP address, a SCAN IP, or a SCAN hostname).

   When the target is an Oracle RAC database, use the rac_hostnames parameter to specify one or more hostnames with DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK. This allows you to take advantage of the high availability capabilities of Oracle RAC. Using an IP address, a SCAN IP, or a SCAN hostname in the rac_hostnames value is not supported.

   For example, with a target Oracle RAC database use the rac_hostnames parameter:

   BEGIN
        DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK(
            db_link_name => 'PRIVATE_ENDPOINT_LINK', 
            rac_hostnames => '["sales1-svr1.example.adb.us-ashburn-1.oraclecloud.com", 
                               "sales1-svr2.example.adb.us-ashburn-1.oraclecloud.com", 
                               "sales1-svr3.example.adb.us-ashburn-1.oraclecloud.com"]', 
            port => '1522',
            service_name => 'exampleServiceName',
            ssl_server_cert_dn => NULL,
            credential_name => 'PRIVATE_ENDPOINT_CRED',
            directory_name => NULL,
            private_target => TRUE);
   END;
   /

   DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK does not support a value of localhost for the hostname or in the rac_hostnames parameter.

   Users other than ADMIN require privileges to run DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK.

   As shown in the example, to create a database link with DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK to a target database on a private endpoint using a secure TCP connection without a wallet, all of the following are required:

   • The directory_name parameter must be NULL.

   • The ssl_server_cert_dn parameter must be NULL.

   • The private_target parameter must be TRUE.

     Note
     
     If you set ROUTE_OUTBOUND_CONNECTIONS to PRIVATE_ENDPOINT, setting the private_target parameter to TRUE is not required in this API. See Enhanced Security for Outbound Connections with Private Endpoints for more information.
3. Use the database link you created to access data in the target database.

   For example:

   SELECT * FROM employees@PRIVATE_ENDPOINT_LINK;
                 

BEGIN
     DBMS_CLOUD.UPDATE_CREDENTIAL (
         credential_name => 'DB_LINK_CRED',
         attribute => 'PASSWORD',
         value => 'password');
END;
/

You can create database links from an Autonomous Database to a target Oracle database that is on a private endpoint.

1. Copy your target database wallet, cwallet.sso, containing the certificates for the target database to Object Store.
   Note
   
   The wallet file, along with the Database user ID and password provide access to data in the target Oracle database. Store wallet files in a secure location. Share wallet files only with authorized users.
2. Create credentials to access your Object Store where you store the cwallet.sso. See CREATE_CREDENTIAL Procedure for information about the username and password parameters for different object storage services.
3. Create a directory on Autonomous Database for the wallet file cwallet.sso.

   For example:

   CREATE DIRECTORY wallet_dir AS 'directory_path_of_your_choice';
                 

   See Create Directory in Autonomous Database for information on creating directories.

4. Use DBMS_CLOUD.GET_OBJECT to upload the target database wallet to the directory you created in the previous step, WALLET_DIR.

   For example:

   BEGIN 
       DBMS_CLOUD.GET_OBJECT(
           credential_name => 'DEF_CRED_NAME',
           object_uri => 'https://objectstorage.us-phoenix-1.oraclecloud.com/n/namespace-string/b/bucketname/o/cwallet.sso',
           directory_name => 'WALLET_DIR'); 
   END;
   /

   In this example, namespace-string is the Oracle Cloud Infrastructure object storage namespace and bucketname is the bucket name. See Understanding Object Storage Namespaces for more information.

   Note
   
   The credential_name you use in this step is the credentials for the Object Store. In the next step you create the credentials to access the target database.
5. On Autonomous Database create credentials to access the target database. The username and password you specify with DBMS_CLOUD.CREATE_CREDENTIAL are the credentials for the target database used within the database link, (where the target database is accessed through the VCN).
   Note
   
   Supplying the credential_name parameter is required.

   For example:

   BEGIN
      DBMS_CLOUD.CREATE_CREDENTIAL(
         credential_name => 'DB_LINK_CRED',
         username => 'NICK',
         password => 'password');
   END;
   /

   The characters in the username parameter must be all uppercase letters.

   Note
   
   You can use a vault secret credential for the target database credential in a database link. See Use Vault Secret Credentials for more information.

   This operation stores the credentials in the database in an encrypted format. You can use any name for the credential name.

6. Create the database link to the target database using DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK.

   For example:

   BEGIN
       DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK(
           db_link_name => 'PEDBLINK1', 
           hostname => 'example1.adb.ap-osaka-1.oraclecloud.com',
           port => '1522',
           service_name => 'example_high.adb.oraclecloud.com',
           ssl_server_cert_dn => 'ssl_server_cert_dn',
           credential_name => 'DB_LINK_CRED',
           directory_name => 'WALLET_DIR',
           private_target => TRUE);
   END;
   /

   Note
   
   If you set ROUTE_OUTBOUND_CONNECTIONS to PRIVATE_ENDPOINT, setting the private_target parameter to TRUE is not required in this API. See Enhanced Security for Outbound Connections with Private Endpoints for more information.

   For a target on a private endpoint, DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK supports specifying a single hostname with the hostname parameter. On a private endpoint, using an IP address, SCAN IP, or a SCAN hostname is not supported (when the target is on a public endpoint, CREATE_DATABASE_LINK supports using an IP address, a SCAN IP, or a SCAN hostname).

   When the target is an Oracle RAC database, use the rac_hostnames parameter to specify one or more hostnames with DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK. This allows you to take advantage of the high availability capabilities of Oracle RAC. Using an IP address, a SCAN IP, or a SCAN hostname in the rac_hostnames value is not supported.

   For example, with a target Oracle RAC database use the rac_hostnames parameter:

   BEGIN
       DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK(
           db_link_name => 'PEDBLINK1', 
           rac_hostnames => '["sales1-svr1.example.adb.us-ashburn-1.oraclecloud.com",
                              "sales1-svr2.example.adb.us-ashburn-1.oraclecloud.com",
                              "sales1-svr3.example.adb.us-ashburn-1.oraclecloud.com"]',
           port => '1522',
           service_name => 'example_high.adb.oraclecloud.com',
           ssl_server_cert_dn => 'ssl_server_cert_dn',
           credential_name => 'DB_LINK_CRED',
           directory_name => 'WALLET_DIR',
           private_target => TRUE);
   END;
   /

   DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK does not support a value of localhost for the hostname or in the rac_hostnames parameter.

   Users other than ADMIN require privileges to run DBMS_CLOUD_ADMIN.CREATE_DATABASE_LINK.

7. Use the database link you created to access data in the target database.

   For example:

   SELECT * FROM employees@PEDBLINK1;
                 

BEGIN
    DBMS_CLOUD.UPDATE_CREDENTIAL (
        credential_name => 'DB_LINK_CRED',
        attribute => 'PASSWORD',
        value => 'password');
END;
/